package com.TestDemo.Test2;
/*
*
* 1.test & && | ||
*
*
* */
public class logicOperation {
    public static void main(String[] args) {
        String XXX = null;

        if(XXX!=null&&!XXX.equals("")){
            System.out.println("XXX!=null&&XXX.equals()" +"NOT is NUll");
        }else {
            System.out.println("XXX!=null&&XXX.equals()" +" is NUll");
        }
/*

        if(XXX!=null&XXX.equals("")){
            System.out.println("XXX!=null&XXX.equals(\"\")");  // NullPointerException
        }

*/

        System.out.println(5&6); // 101  110 -->010
        System.out.println(5|6);  // 101 110 -->111


        System.out.println(4.0-3.6); // 0.3999999999999999


    }
}
